DOCSLIB.ORG

The Production of Metal Mirrors for Use in Astronomy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Production of Metal Mirrors for Use in Astronomy The Production of Metal Mirrors for use in Astronomy A Thesis Submitted to the University of London for the Degree of Doctor of Philosophy by David Brooks UCL Optical Science Laboratory Department of Physics and Astronomy University College London 2001 ProQuest Number: U643140 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest U643140 Published by ProQuest LLC(2015). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. Microform Edition © ProQuest LLC. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 The Production of Metal Mirrors for use in Astronomy Abstract This thesis demonstrates the possibility of manufacturing larger mirrors from nickel coated aluminium with a considerable cost and risk benefits compared to zero expansion glass ceramic or borosilicate. Constructing large mirrors from aluminium could cut the cost of production by one third. A new generation of very large telescopes is being designed, on the order of 100 meters diameter. The proposed designs are of mosaic type mirrors similar to the Keck Telescope primary. The enormous mass of glass required inhibits the construction, simply by its cost and production time. Very little research has been done on the processes involved in the production of large metal mirrors. However the thermal efficiency and potential improved mirror seeing benefits are documented. Space telescopes and optical telecommunications could also benefit with the application of metal mirrors. Presented here are the processes and results that culminated in the rebirth of the Birr Telescope. The main section concerns the material selection and processes in the construction of a 1.83 meter diameter 1.4 tonne aluminium primary mirror. The aluminium mirror technology developed was also applied to the construction of an aspheric thin meniscus deformable mirror. Methods employed in its production are described. Documented are the advanced computer controlled polishing methods employed in producing a one third scale model of the hyperbolic secondary mirror for the Gemini Telescopes. These were developed using an active polishing lap. List of Tables 3.1 Physical properties of potential metal mirror blank materials ......... 55 4.1 Grades of silicon carbide .................................................................. 72 4.2 Composition of silicon carbide ........................................................ 73 4.3 Moh hardness comparison ................................................................ 74 4.4 Polishing compounds for the production of an optical surface on metal . 74 4.5 Aluminium oxide ................................................................................. 75 4.6 Commercially available polishing cloths suitable for polishing metal... 78 5.1 Types of temper as defined by British and European Standard BS EN 515. 97 5.2 Types of aluminium alloy .................................................................... 98 5.3 Mechanical and physical properties of selected alloys ....................... 100 5 .4 Chemical analysis of the composition of the 5083 in “O” condition .... 102 5.5 Grades and quantity of SiC used during grinding ............................... 112 5.6 Typical set of spherometer readings ................................................... 113 5 .7 Hardness of grinding lap materials tested ........................................... 121 5.8 Lapping materials ............................................................................... 123 5.9 Mask dimensions ............................................................................. 135 5.10 Distances are away from the mirror ................................................... 135 5.11 Typical data set measured at focus ..................................................... 138 9.1 Slip gauge settings for the ten-probe profilometer ............................. 207 List of Figures 2.1 German type polishing machine at OSL .............................................. 35 2.2 General layout of a German type polishing machine ............................ 36 2.3 The general layout of a Draper type polishing machine ......................... 37 2.4 Mismatch of form when de-centring the lap .......................................... 39 2.5 The ERP-600 aspheric polishing machine ............................................... 48 3.1 Final interferogram of the test mirror .................................................... 66 3.2 Test samples ........................................................................................... 68 4.1a Polishing cloth and compound, surface finish comparison .................... 81 4. lb Detailed view of textures achieved .......................................................... 82 4.2 Surface texture produced by 1 micron AI 3 O2 and MultiTex ................... 83 4.3 Surface texture produced on aluminium ................................................. 83 4.4 Surface polished with 0.3 micron alumina and MultiTex ....................... 84 4.5 Micro scratches ....................................................................................... 85 4.6 Micrographs of alumina powder (300X) and particle size distribution . 85 4.7 MultiTex polishing cloth ........................................................................... 86 5.1 Side view of the telescope ....................................................................... 88 5.2 Diagram of proposed warping harness ..................................................... 96 5.3 Turning the 1.4 m dia lap ......................................................................... 108 5.4 Diagram of the initial contact area of the lap ........................................... 112 5.5 Example centre to edge mirror profile ..................................................... 114 5.6 1.4 m lap with cloth facets ....................................................................... 116 5.7 Damage polishing cloth ........................................................................... 117 5.8 Test path dimensions ............................................................................... 118 5.9 Lead lap facet with inclusion ................................................................... 121 5.10 Perspex faced lap ..................................................................................... 124 5.11 Optical test path rooms ............................................................................. 125 5.12 Enhanced video image of 10.6 micron fringes on polished aluminium . 126 5.13 Histogram of nickel c o a t ......................................................................... 130 5.14 Nickel plated witness piece, bend test ..................................................... 130 5.15 Surface pitting ......................................................................................... 131 5.16 Magnified image of pits ......................................................................... 131 5.17 Null test arrangement ............................................................................. 136 5.18 Aspheric departure ................................................................................. 137 5.19 Typical graph of the slope differences (centre to edge) ........................... 138 5.20 The final zonal measurement (centre to edge) ......................................... 140 5 .21 Image spread at focal plane ..................................................................... 140 5.22 Testing the mirror on the support ............................................................. 142 5.23 Disk of least confusion at the focal plane ................................................. 142 5.24 F.E.A. of mirror segment ......................................................................... 145 5.25 The primary mirror after turning ............................................................. 148 5.26 The primary being nickel coated at Nitec ............................................... 148 5.27 The primary mounted on the polishing machine .................................... 149 5.28 The primary mounted in the test support frame....................................... 149 6.1 The Birr Telescope ................................................................................... 150 6.2 Installing the primary mirror ................................................................... 152 6.3 Diagram of the mirror box ....................................................................... 153 6.4 Mirror box at the base of the telescope ................................................... 154 6.5 The telescope tube .................................................................................... 155 6.6 The universal joint and jacking screws ................................................... 156 6.7 The Newtonian mirror and support ......................................................... 157 6.8 The eyepiece interchange .......................................................................... 159 6.9 The Moon taken through the Birr Telescope .............................................. 161 6.10 Staining of the mirror surface .................................................................
Load more

Recommended publications
  • Telescopes and Binoculars
    Continuing Education Course Approved by the American Board of Opticianry Telescopes and Binoculars National Academy of Opticianry 8401 Corporate Drive #605 Landover, MD 20785 800-229-4828 phone 301-577-3880 fax www.nao.org Copyright© 2015 by the National Academy of Opticianry. All rights reserved. No part of this text may be reproduced without permission in writing from the publisher. 2 National Academy of Opticianry PREFACE: This continuing education course was prepared under the auspices of the National Academy of Opticianry and is designed to be convenient, cost effective and practical for the Optician. The skills and knowledge required to practice the profession of Opticianry will continue to change in the future as advances in technology are applied to the eye care specialty. Higher rates of obsolescence will result in an increased tempo of change as well as knowledge to meet these changes. The National Academy of Opticianry recognizes the need to provide a Continuing Education Program for all Opticians. This course has been developed as a part of the overall program to enable Opticians to develop and improve their technical knowledge and skills in their chosen profession. The National Academy of Opticianry INSTRUCTIONS: Read and study the material. After you feel that you understand the material thoroughly take the test following the instructions given at the beginning of the test. Upon completion of the test, mail the answer sheet to the National Academy of Opticianry, 8401 Corporate Drive, Suite 605, Landover, Maryland 20785 or fax it to 301-577-3880. Be sure you complete the evaluation form on the answer sheet.
    [Show full text]
  • Microstructures and Mechanical Properties of AA- 5754 and AA-6061 Aluminum Alloys Formed by Single Point Incremental Forming Process
    Microstructures and Mechanical properties of AA- 5754 and AA-6061 Aluminum alloys formed by Single Point Incremental Forming Process Sahand Pourhassan Shamchi Submitted to the Institute of Graduate Studies and Research in partial fulfillment of the requirements for the Degree of Master of Science in Mechanical Engineering Eastern Mediterranean University September 2014 Gazimağusa, North Cyprus Approval of the Institute of Graduate Studies and Research _____________________________________ Prof. Dr. Elvan Yilmaz Director I certify that this thesis satisfies the requirements as a thesis for the degree of Master of Science in Mechanical Engineering. ________________________________ Prof. Dr. Uğur Atikol Chair, department of Mechanical Engineering We certify that we have read this thesis and that in our opinion it is fully adequate in scope and quality as a thesis for the degree of Master of Science in Mechanical Engineering. _____________________________________ Asst. Prof. Dr. Ghulam Hussain Supervisor Examining Committee 1. Prof. Dr. Fuat Egelioğlu __________________________ 2. Prof. Dr. Majid Hashemipour __________________________ 3. Asst. Prof. Dr.Ghulam Hussain __________________________ ABSTRACT Single point incremental forming (SPIF) process is considered as a cost-effective method to fabricate sheet metals because there is no need for dedicated dies which are used in other conventional processes. Due to the capability of forming sheets on CNC machines, the flexibility of this process is high which allows the operator to modify the geometry of the product much easier than the other methods like stamping. This study is carried out to investigate the effects of different forming parameters on the mechanical properties and microstructures of formed parts. The effects of wall angle, feed rate, spindle speed and lubrication are explored on AA5754 and AA6061 Aluminium Alloys.
    [Show full text]
  • A Newly-Discovered Accurate Early Drawing of M51, the Whirlpool Nebula
    Journal of Astronomical History and Heritage , 11(2), 107-115 (2008). A NEWLY-DISCOVERED ACCURATE EARLY DRAWING OF M51, THE WHIRLPOOL NEBULA William Tobin 6 rue Saint Louis, 56000 Vannes, France. E-mail: [email protected] and J.B. Holberg Lunar and Planetary Laboratory, University of Arizona, 1541 East University Boulevard, Tucson, AZ 85721, U.S.A. E-mail: [email protected] Abstract: We have discovered a lost drawing of M51, the nebula in which spiral structure was first discovered by Lord Rosse. The drawing was made in April 1862 by Jean Chacornac at the Paris Observatory using Léon Foucault’s newly-completed 80-cm silvered-glass reflecting telescope. Comparison with modern images shows that Chacornac’s drawing was more accurate with respect to gross structure and showed fainter details than any other nineteenth century drawing, although its superiority would not have been apparent at the time without nebular photography to provide a standard against which to judge drawing quality. M51 is now known as the Whirlpool Nebula, but the astronomical appropriation of ‘whirlpool’ predates Rosse’s discovery. Keywords: reflecting telescopes, nebulae, spiral structure, Léon Foucault, Lord Rosse, M51, Whirlpool Nebula 1 REFLECTING TELESCOPES AND SPIRAL STRUCTURE The French physicist Léon Foucault (1819–1868) is the father of the reflecting telescope in its modern form, with large, optically-perfect, metallized glass or ceramic mirrors. Foucault achieved this breakthrough while working as ‘physicist’ at the Paris Observatory in the late 1850s. The largest telescope that he built (Foucault, 1862) had a silvered-glass, f/5.6 primary mirror of 80-cm diameter in a Newtonian configura- tion (see Figure 1).
    [Show full text]
  • Dissimilar Materials of Friction Stir Welding - Overview
    International Journal of Engineering Trends and Technology (IJETT) – Volume-44 Number-3 -February 2017 Dissimilar Materials of Friction Stir Welding - Overview K. Nagendra Kumar1, P. Ravikanth Raju2 1Asistance Professor, Department of Mechanical Engineering, Bhaskar Engineering College, Yenkapally, Moinabad (M), R.R.(Dist), Hyderabad-500075, Telangana State, India. 2Department of Mechanical Engineering, Anurag Group of Institutions, Venkatapur (V), Ghatkesar (M), R.R. Dist -500088, Telangana State, India Abstract - Friction Stir Welding is a joining process welding of metal-to-polymer is given greater which involves the deformation of materials. In this emphasis in this section than metal to- metal and process tool will generate the pressure and polymer-to-polymer welding, since metal-to- temperature and form solid state weld. This process polymer is a novel technique and there are fewer is suitable for joining different materials, different publications in this area [15]. The schematic mechanical and chemical properties, and different representation of FSW process is shown in Fig. material structures. Fusion welding processes 1. exhibits poor weldability by Welding of dissimilar aluminium alloys. Because of thin oxide layer formation, oxide layer tends to thicken at higher temperatures on the surface of aluminium alloys. This review addresses the Friction stir welding overview which includes the basic concept of the process, microstructure formation, influencing process parameters, typical defects in FSW process and some recent applications. The paper will also discuss some of the process variants of FSW such as Friction Stir Processing. Keywords - Tool rotational speed, Friction Stir welding, dissimilar aluminium alloy. 1. INTRODUCTION Fig 1: FSW Process [14] FSW was invented in UK in December, 1991 at The shoulder is pressed against the surface of the The Welding Institute (TWI).
    [Show full text]
  • THE VACUUM CHAMBERIN the INTERACTION REGIÓN of PARTIÓLE COLLIDERS: a HISTORICAL STUDY and DEVELOPMENTS IMPLEMENTED in the Lhcb EXPERIMENT at CERN
    Departamento de Física Aplicada a la Ingeniería Industrial Escuela Técnica Superior de Ingenieros Industriales THE VACUUM CHAMBERIN THE INTERACTION REGIÓN OF PARTIÓLE COLLIDERS: A HISTORICAL STUDY AND DEVELOPMENTS IMPLEMENTED IN THE LHCb EXPERIMENT AT CERN Autor: Juan Ramón Klnaster Refolio Ingeniero Industrial por la E.T.S.I. Industriales Universidad Politécnica de Madrid Directores: Raymond J.M. Veness Ph; D. Mechanics of Materials and Plasticity University of Leicester (England) Linarejos Gámez Mejías Doctor Ingeniero Industrial por la E.T.S.I.I. Universidad Politécnica de Madrid 2004 Whatever you dream, you can do, begin it! Boldness has power, magic and genius in it Goethe Homo sum: humani nihil a me alienum puto (Je suis homme, et rien de ce que est humain ne m'est étraxiger) Terence Loving softly and deeply... Elsje Tout proche d'étre un Boudha paresseusement réve le vieux pin Issa En nuestra cabeza, en nuestro pecho es donde están los circos en que, vestidos con los disfraces del tiempo, se enfrentan la Libertad y el Destino Jünger This Thesis has been possible thanks to the support of many people that duñng last 15 months have helped me in different ways. I would like to thank my co- lleagues R. Aehy, P. Bryant, B. Calcagno, G. Corii, A. Gerardin, G. Foffano, M. Goossens, C. Hauvüler, H. Kos, J. Kruzelecki, P. Lutkiewicz, T. Nakada, A. Rossi, J.A. Rubio, B. Szybinski, D. Tristram, B. Ver- solatto, L. Vos and W. Witzeling for their contribu- tions in different moments. Neither would I have ever managed to finish it without those moments of peace shared with mes fréres d'Independance et Verité á VOr :.
    [Show full text]
  • Aplea for Reflectors
    A PLEA FOR REFLECTORS Pedro RÉ http://pedroreastrophotography.com/ In 1867 John Browing (c1833-1925)1 published a trade catalogue entitled “A Plea for Reflectors: Being a Description of the New Astronomical Telescopes with Silvered-Glass Specula; And Instructions for adjusting and Using Them”. This catalogue had six editions that were published until 18762. Browning describes his range of reflecting telescopes, how to use them and compares these with achromatic refractors of comparable apertures. It also contains numerous details of its extensive range of glass silvered specula, eyepieces, micrometres, barometers and microscopes (Figure 1). The back of the booklet contains testimonials from satisfied customers, many of them distinguished amateurs and professionals. By publishing “A Plea for Reflectors”, J. Browning & Co. became one of the first to mass produce telescopes for the amateur (Figure 2). The popularity of the Newtonian reflector as the instrument of choice for the amateur astronomer followed the pioneering work of George Henry With (1827-1904). With began making silvered-glass mirrors in the early 1860's following his retirement as schoolmaster at the Blue Coat School, Hereford. With did not actually make telescopes. His principal customer was John Browning, the London instrument maker well-known for his spectroscopes and telescopes. Browning's business flourished to circa 1905, possibly first starting at 1 Norfolk Street, Strand circa 1866. The firm had their 'factory' in Vine Street EC3 (1872-76) and Southampton Street north off the Strand (1877-82) and William Street (1887). The shop was at 111 Minories (near Tower Hill) working under the name Spencer, Browning and Co.
    [Show full text]
  • The Herschels and Their Astronomy
    The Herschels and their Astronomy Mary Kay Hemenway 24 March 2005 outline • William Herschel • Herschel telescopes • Caroline Herschel • Considerations of the Milky Way • William Herschel’s discoveries • John Herschel Wm. Herschel (1738-1822) • Born Friedrich Wilhelm Herschel in Hanover, Germany • A bandboy with the Hanoverian Guards, later served in the military; his father helped him to leave Germany for England in 1757 • Musician in Bath • He read Smith's Harmonies, and followed by reading Smith's Optics - it changed his life. Miniature portrait from 1764 Discovery of Uranus 1781 • William Herschel used a seven-foot Newtonian telescope • "in the quartile near zeta Tauri the lowest of the two is a curious either Nebulous Star or perhaps a Comet” • He called it “Georgium Sidus" after his new patron, George Ill. • Pension of 200 pounds a year and knighted, the "King's Astronomer” -- now astronomy full time. Sir William Herschel • Those who had received a classical education in astronomy agreed that their job was to study the sun, moon, planets, comets, individual stars. • Herschel acted like a naturalist, collecting specimens in great numbers, counting and classifying them, and later trying to organize some into life cycles. • Before his discovery of Uranus, Fellows of the Royal Society had contempt for his ignorance of basic procedures and conventions. Isaac Newton's reflecting telescope 1671 William Herschel's 20-foot, 1783 Account of some Observations tending to investigate the Construction of the Heavens Philosophical Transactions of the Royal Society of London (1784) vol. 74, pp. 437-451 In a former paper I mentioned, that a more powerful instrument was preparing for continuing my reviews of the heavens.
    [Show full text]
  • 5754 Aluminium Technical Datasheet Commercial Aluminium Alloy Service
    5754 Aluminium Technical Datasheet Commercial Aluminium Alloy Service. Quality. Value. Applications Key features: • Shipbuilding • Excellent resistance to seawater & industrial chemical • Food processing equipment corrosion • Treadplate • Higher in strength than 5251 • Vehicle bodies • Excellent weldability • Fishing industry equipment • Very good workability • Welded chemical & nuclear structures Product Description Related Material Specifications 5754 aluminium alloy offers extremely good resistance to • A95754 • Al Mg3 both seawater corrosion and industrially polluted • Al 3.1Mg Mn Cr • AW-5754 atmospheres. Higher in strength than 5251, the alloy has excellent weldability and very good workability. 5754 is used in applications in market sectors such as marine, oil, Weldability & gas, chemical and nuclear. Excellent weldabilty (brazability is poor) Availability Corrosion Resistance Highly resistant to both seawater and industrial chemical Plate, Sheet attack. Chemical Composition (weight %) Weight (%) Mn Fe Mg Si Al min 2.60 Bal max. 0.50 0.40 3.20 0.40 Bal Mechanical Properties Physical Properties Tensile Strength 245 - 290 MPa Density 2.66 g/cm³ Elongation A50 mm 10 - 15% Melting Point 600°C Proof Stress 185 - 245 MPa Thermal Expansion 24 x10-6 /K Modulus of Elasticity 68 GPa Thermal Conductivity 147 W/m.K The properties above are for material in the H22 condition Technical Assistance Our knowledgeable staff backed up by our resident team of qualified metallurgists and engineers, will be pleased to assist further on any technical topic. www.smithmetal.com [email protected] Biggleswade Birmingham Bristol Chelmsford Gateshead Horsham Leeds 01767 604604 0121 7284940 0117 9712800 01245 466664 0191 4695428 01403 261981 0113 3075167 London Manchester Nottingham Norwich Redruth Verwood General 020 72412430 0161 7948650 0115 9254801 01603 789878 01209 315512 01202 824347 0845 5273331 1930 All information in our data sheet is based on approximate testing and is stated to the best of our knowledge and belief.
    [Show full text]
  • A 'Catchers Tale' the 'Leviathan Lord'
    The ‘Leviathan Lord’ of Birr Castle The ‘Leviathan Lord’ of Birr Castle William Parsons, 3rd Earl of Rosse A ‘Catchers Tale’ Featuring Featuringthe Forgotten the Forgotten LivesLives of theof Men the and Men Women and who FirstWomen who First PhotographedPhotographed the Heavens the Heavens Stefan Hughes Contents 1. The ‘Catchers Tales’ 1 1.1 Introduction 2 1.2 Birr Castle Today 4 1.3 The ‘Great Telescope Builder’ 5 2. The Life and Work of William Parsons 6 2.1 ‘Great Telescopes’ 7 2.2 Lord Oxmantown 8 2.3 Mary Field of Heaton Hall 10 2.4 Parsonstown 17 2.5 Mirror, Mirror on the Estate... 23 2.6 The ‘Leviathan’ 30 2.7 ‘The Problem of the Nebulae’ 36 2.8 ‘Spirals’ 44 2.9 Photography at Birr 50 2.10 Homage 54 2.11 After... 58 3. Appendices 64 A: William Parsons: Family Pedigree 65 B: Mary Field: Family Pedigree 69 C: Glossary of Terms & Personalities 73 4. End Piece 80 Notes & Bibliography 81 Acknowledgements 91 Index 92 The Author 97 i 1. The ‘Catchers Tales’ Catchers of the Light William Parsons 3rd Earl of Rosse The Forgotten Lives of the Men and Women who First Photographed the Heavens Their True Tales of Adventure, Adversity & Triumph Stefan Hughes1 1.1 Introduction The ‘Catchers Tales’, each feature a single life of one of the men and women who first photographed the heavens. Their lives are ones full of adventure, adversity and triumph - which would test the abilities of even the best author or screenwriter to recreate as a work of fiction.
    [Show full text]
  • DRAFT Pren 286-4
    SLOVENSKI STANDARD oSIST prEN 286-4:2019 01-november-2019 Enostavne neogrevane (nekurjene) tlačne posode, namenjene za zrak ali dušik - 4. del: Tlačne posode iz aluminijevih zlitin za zračne zavore in pomožno pnevmatsko opremo na tirnih vozilih Simple unfired pressure vessels designed to contain air or nitrogen - Part 4: Aluminium alloy pressure vessels designed for air braking equipment and auxiliary pneumatic equipment for railway rolling stock Einfache unbefeuerte DruckbehälteriTeh STA fürN DLuftA oderRD Stickstoff PREV - TeilIE W4: Druckbehälter aus Aluminiumlegierungen für Druckluftbremsanlagen(standards.i tundeh .pneumatischeai) Hilfseinrichtungen in Schienenfahrzeugen oSIST prEN 286-4:2019 https://standards.iteh.ai/catalog/standards/sist/fad6ce8c-8fbd-4c96-98f9- Récipients à pression simples, non24b 8soumisf6b90ff4/o sàis tla-pr eflamme,n-286-4-20 destinés19 à contenir de l'air ou de l'azote - Partie 4 : Récipients à pression en alliages d'aluminium destinés aux équipements pneumatiques de freinage et aux équipements pneumatiques auxiliaires du matériel roulant ferroviaire Ta slovenski standard je istoveten z: prEN 286-4 ICS: 23.020.32 Tlačne posode Pressure vessels 45.040 Materiali in deli za železniško Materials and components tehniko for railway engineering 77.150.10 Aluminijski izdelki Aluminium products oSIST prEN 286-4:2019 en,fr,de 2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno. oSIST prEN 286-4:2019 iTeh STANDARD PREVIEW (standards.iteh.ai) oSIST prEN 286-4:2019
    [Show full text]
  • Couplant Effect and Evaluation of FSW AA6061-T6 Butt Welded Joint
    COPYRIGHT AND CITATION CONSIDERATIONS FOR THIS THESIS/ DISSERTATION o Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. o NonCommercial — You may not use the material for commercial purposes. o ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original. How to cite this thesis Surname, Initial(s). (2012) Title of the thesis or dissertation. PhD. (Chemistry)/ M.Sc. (Physics)/ M.A. (Philosophy)/M.Com. (Finance) etc. [Unpublished]: University of Johannesburg. Retrieved from: https://ujcontent.uj.ac.za/vital/access/manager/Index?site_name=Research%20Output (Accessed: Date). Couplant Effect and Evaluation of FSW AA6061-T6 Butt Welded Joint By Itai Mumvenge 217093863 Submitted in partial fulfilment of the requirements for the degree of Master of Engineering in Mechanical Engineering In the Department of Mechanical Engineering Science Of the Faculty of Engineering and the Built Environment At the University of Johannesburg, South Africa Supervisor: Dr Stephen A. Akinlabi Co-Supervisor: Dr Peter M. Mashinini November, 2017 i 1. DEDICATION This dissertation is dedicated to my late grandmother Esnath Mvenge ii 2. COPYRIGHT STATEMENT The copyright of this dissertation is owned by the University of Johannesburg, South Africa. No information derived from this publication may be published without the author’s prior consent, unless correctly referenced. ………………………………….. 25 November 2017 Author’s Signature Date: iii 3. AUTHOR DECLARATION I, Mumvenge Itai hereby declare that the research work documented in this dissertation is my own, and no portion of the work has been submitted in support of an application for another degree or qualification at this or any other university or institute of learning.
    [Show full text]
  • Advanced Materials for Light Weight Body Design
    ISSN (Online): 2319-8753 ISSN (Print) : 2347-6710 International Journal of Innovative Research in Science, Engineering and Technology (A High Impact Factor, Monthly, Peer Reviewed Journal) Visit: www.ijirset.com Vol. 7, Issue 1, January 2018 Advanced Materials for Light Weight Body Design Tejas Pawar1, Atul Ekad2, Nitish Yeole3, Aditya Kulkarni4, Ajinkya Taksale5 BE-Mech. (2016), Dept. of Mechanical Engineering, VIIT, Pune, India.1 BE-Mech. (2016), Dept. of Mechanical Engineering, NBN Sinhgad School of Engineering, Pune, India.2 BE-Mech. (2016), Dept. of Mechanical Engineering, NBN Sinhgad School of Engineering, Pune, India.3 BE-Mech. (2017), Dept. of Mechanical Engineering, RMD Sinhgad School of Engineering, Pune, India.4 BE-Mech. (2016), Dept. of Mechanical Engineering, VPK Bajaj Inst. of Engg. & Technology, Baramati, India.5 ABSTRACT: With the emergent industrial development and dependence on fossil fuels, Green House Gas (GHG) emission has become most important problem. However, car manufacturers have to remain in competition with peers and design their products innovatively that fulfil the new regulations too. Nevertheless of various different approaches to improve fuel economy such as enhancing fuel quality, development of high performance engines and fuel injection system, weight reduction is one of the encouraging approaches. With 10% weight reduction in passenger cars, the fuel economy improves by as much as 6–8%. KEYWORDS: Carbon Fibre, Magnesium, Aluminium, Titanium, light-weight body materials, poly-acrylonitrile I. INTRODUCTION Car body design in view of structural performance and weight reduction is a challenging task due to the various performance objectives that must be satisfied such as vehicle safety, fuel efficiency, endurance and ride quality.
    [Show full text]